Method of manufacturing magnetoresistance element and storage medium used in the manufacturing method

Abstract

An embodiment of the invention provides a method of manufacturing a magnetoresistance element with an MR ratio higher than that of the related art. A method of manufacturing a magnetoresistance element includes a step of forming a magnetization fixed layer, a magnetization free layer, and a tunnel barrier layer provided between the magnetization fixed layer and the magnetization free layer on a substrate. In the method, the tunnel barrier layer is formed by arranging a target that has a diameter smaller than that of the substrate, contains a magnesium oxide sintered body, and has a relative density 90 % or more so as to be inclined with respect to a surface to be deposited of the substrate, and forming a magnesium oxide layer using a sputtering method while rotating the substrate.

1 . A method of manufacturing a magnetoresistance element comprising:
 a step of forming a magnetization fixed layer, a magnetization free layer, and a tunnel barrier layer provided between the magnetization fixed layer and the magnetization free layer on a substrate using a sputtering method,   wherein the step of forming the tunnel barrier layer includes a step of forming a crystalline magnesium oxide layer by the sputtering method using a target which contains a magnesium oxide sintered body and has a relative density of 90% or more.   
     
     
         2 . The method of manufacturing a magnetoresistance element according to  claim 1 , wherein the relative density of the target is in the range of 95.0% to 99.9%. 
     
     
         3 . The method of manufacturing a magnetoresistance element according to  claim 1 , wherein, in the step of forming the tunnel barrier layer, the diameter of the target is smaller than that of the substrate, the target and the substrate are arranged such that a normal line passing through the center of the target intersects a normal line passing through the center of the substrate, and the crystalline magnesium oxide layer is formed by the sputtering method while the substrate is rotated. 
     
     
         4 . The method of manufacturing a magnetoresistance element according to  claim 3 , wherein, in the step of forming the tunnel barrier layer, the substrate is rotated at a rotational speed of 30 rpm or more. 
     
     
         5 . (canceled) 
     
     
         6 . The method of manufacturing a magnetoresistance element according to  claim 3 , wherein, in the step of forming the tunnel barrier layer, the normal line passing through the center of the target intersects the normal line passing through the center of the substrate at an angle of 1° to 60°. 
     
     
         7 . (canceled) 
     
     
         8 . The method of manufacturing a magnetoresistance element according to  claim 3 , wherein, in the step of forming the tunnel barrier layer, the radius D of the target and the radius d of the substrate satisfy 0.01 d≦D≦0.90 d. 
     
     
         9 . (canceled) 
     
     
         10 . The method of manufacturing a magnetoresistance element according to  claim 3 , wherein, in the step of forming the tunnel barrier layer, a line extending in the plane direction of the substrate intersects the normal line passing through the center of the target at a position that is away from the center of the substrate. 
     
     
         11 . The method of manufacturing a magnetoresistance element according to  claim 10 , wherein, in the step of forming the tunnel barrier layer, the line extending in the plane direction of the substrate intersects the normal line passing through the center of the target at a position that is away from the outer circumference of the substrate. 
     
     
         12 .- 22 . (canceled) 
     
     
         23 . The method of manufacturing a magnetoresistance element according to  claim 1 , wherein the sputtering method using the target which contains the magnesium oxide sintered body and has a relative density of 90% or more is performed at a deposition rate of 1 nm/sec or less. 
     
     
         24 . The method of manufacturing a magnetoresistance element according to  claim 1 , wherein the sputtering method using the target which contains the magnesium oxide sintered body and has a relative density of 90% or more is performed at a sputtering gas pressure of 0.4 Pa or less. 
     
     
         25 . The method of manufacturing a magnetoresistance element according to  claim 1 , wherein the sputtering method using the target which contains the magnesium oxide sintered body and has a relative density of 90% or more is performed at a deposition rate of 1 nm/sec or less and a sputtering gas pressure of 0.4 Pa or less.